The purpose of this thesis was to calculate the three-dimensional moments at the hip joint due to external forces applied to the lower limb during ambulation. In order to accurately compute the moments at the hip, the precise location of hip joint center (HJC) had to be defined. An anatomical study of adult human cadaveric pelves was initiated to investigate the correlation between HIC and pelvic geometry. Pearson product-moment correlations revealed that HJC could be accurately located relative to the anterior superior iliac spline (A518) 14% of pelvic width medial, 34% of pelvic depth posterior, and 80% of pelvic height inferior. With the location of HIC defined, the quasi-static hip joint moments were calculated during the stance phase of gait. Power in the plane of progression and actual power at the hip joint were also defined and calculated during the stance phase of gait.